The paired bone that contains the middle and inner ear, and so protects the organs of hearing and balance
Temporal bone — the petrous part holds the cochlea and semicircular canals.
Anatomy · Bones
Temporal bone
Home of the ear
Skull · cranium
The paired temporal bones form the lower sides and part of the base of the skull, at the temples. Each houses the middle and inner ear, carries the canal for the facial nerve, and forms the socket of the jaw joint. Five parts are recognised: squamous, tympanic, petromastoid (mastoid and petrous), and the zygomatic and styloid processes.
How to spot them
- ▸A paired bone on the lower side of the skull, in front of and around the ear opening
- ▸The mastoid process is the bony lump you can feel behind the ear, and the styloid process is a slender spike below the ear canal
- ▸A long bar, the zygomatic process, runs forward to meet the cheekbone and form the zygomatic arch
- ▸A pyramid of very dense bone, the petrous part, sits inside the skull base and holds the inner ear
What to know
The bony lump felt just behind the ear, honeycombed with air cells that can become infected after a middle ear infection
Temporal bone — the mastoid process, and mastoiditis.
Its socket, the mandibular fossa, forms the upper half of the jaw joint
Temporal bone — with the mandible it forms the temporomandibular joint.
A slender, pen-shaped spike below the ear canal anchors the ligament that supports the hyoid bone
Temporal bone — the styloid process and the stylohyoid ligament.
Its forward-projecting process joins the cheekbone to make the arch on which the masseter muscle originates
Temporal bone — the zygomatic process, forming the zygomatic arch with the zygomatic bone.
The facial nerve travels through a canal in this bone, so a fracture here can cause facial paralysis and hearing loss
Temporal bone — fractures follow blunt trauma to the side of the skull.
Its name is said to come from the Latin for time, because the region it underlies is where hair typically first turns grey
Temporal bone — from the Latin tempus, time.
Key ideas
- Five parts: the flat squamous part above, the tympanic part around the ear canal, the petrous and mastoid parts behind and beneath, the zygomatic process in front and the styloid process below.
- The internal acoustic meatus on the inside of the petrous ridge carries the facial and vestibulocochlear nerves into the bone.
Quick-fire facts
- •Petrous is from the Latin for rocky; the petrous part is among the densest bone in the body
- •The squamous part meets the parietal bone at the squamous suture and the greater wing of the sphenoid at the pterion
- •The temporal bone articulates with the mandible, zygomatic, sphenoid, parietal and occipital bones
- •Sternocleidomastoid, splenius capitis and the posterior belly of digastric all attach to the mastoid process
- •The temporalis muscle arises from the temporal fossa, including the squamous part of the bone
- •The external acoustic meatus (ear canal) opens through the tympanic part
- •Mastoid air cells help equalise pressure in the middle ear
- •Petrous ridges divide the middle from the posterior cranial fossa
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Sources
- TeachMeAnatomy — The Temporal Bone
- OpenStax — Anatomy and Physiology 2e, 7.2 The Skull